Process fob improving the fastness



Patented Nov. 29, 1938 UNITED STATES PATENT OFFICE PROCESS FOR IMPROVING THE FASTNESS OF DYEINGS No; Drawing. Original application March 27, 1936, Serial No. 71,172. Divided and this-application September 24, 1937, Serial No. 165,482. In Germany April 3, 1935 3 Claims.

The present application is a division of our application Serial No. 71,172, filed March 27, 1936 relating to Expedients useful for improving the fastness of dyeings.

Our present invention relates to a process for improving the fastness of dyeings which have been prepared on cellulose materials by means of substantive dyestufis.

It is well known that dyeings obtained on cellulose materials by means of substantive dyestuffs can be improved as regardsu-fastness by treatment with salts of certain organic bases. A great number of such bases has already been proposed for this purpose. Most of them are characterized by the fact that they contain in the molecule a long aliphatic carbon chain of at least 7 carbon atoms.

Such bases are capable of improving the fastness to water and to cross dyeings and-as far as they contain pentavalent nitrogen-to perspiration, but they can not substantially improve the fastness to washing which is of considerably more importance.

Our present invention has for its object the after-treatment of such dyeings with solutions containing products containing a pyridine radicle the ring nitrogen atom of which is converted into the pentavalent state, and a member of the group consisting of a radicle of dichloro-diacetyl-L4- phenylenediamine and of symmetrical dichloroacetone.

The favorable effect of the present compounds is obtained by the fact that they do not contain a long aliphatic chain and that therefore their reaction products with dyestuif acids are insoluble not only in water but also in solutions of soaps. By the fact that they contain the nitrogen atom of basic character in the highest valency the fact is obtained that the salts of these compounds with the dyestufl-acids of the used substantive dyestuffs are not decomposed by the alkali used for washing the dyeings.

In order to further illustrate our invention the following examples are given, the parts being by weight and all temperatures in degrees centigrade. We wish it, however, to be understood that our invention is not limited to the particular products nor reaction conditions mentioned therein.

Example 1 54 parts of 1.4-phenylenediamine are dissolved in 500 parts of water. Then parts of sodium carbonate are added and 120 parts of chloracetyl chloride are slowly poured in at about 0 to 5 C. The precipitate formed which is the dichlorodlacetyl-1.4- phenylene-diamine of the following formula:

NH-OOCHPCl NELCOC Hz-Cl is washed with cold and hot water and alcohol.

50 parts thereof are mixed with 100 parts of pyridine and the mixture is heated to about 100 for 20 hours. The precipitate formed is washed with alcohol and dried. It may be freed from unaltered initial material by redissolving in water, filtering the solution thus obtained and precipitating it by the addition of sodium chloride or alcohol. A dyeing obtained on cotton by means of 3% of Sirius blue BR (Schultz, Farbstofftabellen, 7th edition, vol. 2, page 197) which is aftertreated for half an hour at about 30' with a solution containing 2 grs. of the above product per liter exhibits a very good fastness to washing. The new product is when dry a light brown powder easily soluble in water and insoluble in alcohol.

Example 2 parts of 2.6-diaminopyridine (see German Patent No. 399,902) and 46 parts of symmetrical dichloro-acetone are dissolved in chloro-benzene and the solution obtained is heated tountil the precipitation is finished. The precipitate formed is washed withchlorobenzene and the hydrochloride of the base thus obtained is dissolved in water. The solution obtained is treated with 400 parts of dimethyl sulfate in the presence of an excess of alkali at room temperature until the dimethyl sulfate is decomposed.

The new base exhibits a similar effect to dye. ings obtained by means of substantive dyestuffs as the above described product.

Example 3 A dyeing obtained on cotton with 3% of Brillantbenzoviolett BBH (Schultz, Farbstofitabellen, 7th edition, supplement vol. I, page 73) is treated for half an hour at 30 with a solution of 1 gr. per liter of a pyridinium base (described in the German Patent No. 551,872, Example 4) of a resin which is obtained by starting from a technical cresol mixture and by acting thereupon with formaldehyde inthe presence of hydrochloric acid.

The dyeing thus treated exhibits a considerably increased fastness to washing.

We claim:

1. Process for improving the tastness oi dyeings which have been prepared on cellulose materials by means of substantive dyestuffs by ai'tertreating them with solutions containing products containing a pyridine radicle the ring nitrogen atom of .which is converted into the pentavalent state, said products being obtained by the action 01 pyridine on a member 01' the group consisting of dichloro-diacetyl-1.4-pheny1enediamine and symmetrical dichioroacetone.

2. Process for improving the tastness of dyeings which have been prepared on cellulose materials by means of substantive dyestuffs by aftertreating them with solutions containing a product obtained by the action of pyridine on dichlorodiacetyl-1.4-pheny1enediamine of the formula:

mr-ooom-m NH-COCHr-Cl which product is when dry 9, light brown powder easily soluble in water and insoluble in alcohol.

3. Process for i proving the Iastness bi dyeings which have been prepared on cellulose materials by means of substantive dyestuffs by aftertreating them with solutions containing a product obtained by condensing 2.6-diaminopyridine with symmetrical dichloroacetone and acting on the reaction product with dimethylsuliate in an alkaline medium.

mnmanp Mtinz. KARL KELLER- o'rro mosxmr, 

